Guide wire with soldered multilayer coil member

ABSTRACT

A guide wire includes an elongate core section and a flexible member disposed on the distal end, the flexible member including a first wire wound into an inner helical coil in a first direction and a second wire wound into an outer helical coil wrapped about the first helical coil in the opposite direction. The two combined helical coils add stiffness and torque transmission to the guide wire without sacrificing tactile feedback.

BACKGROUND

This invention relates to the field of guide wires for advancingintraluminal devices such as stent delivery catheters, balloondilatation catheters, atherectomy catheters and the like within apatient's body, such as within a patient's vasculature.

In a typical percutaneous procedure in a patient's coronary system, aguiding catheter having a preformed distal tip is percutaneouslyintroduced into a patient's peripheral artery, e.g. femoral, radial orbrachial artery, by means of a conventional Seldinger technique andadvanced therein until the distal tip of the guiding catheter is seatedin the ostium of a desired coronary artery. There are two basictechniques for advancing a guide wire into the desired location withinthe patient's coronary anatomy, the first is a preload technique whichis used primarily for over-the-wire (OTW) devices and the bare wiretechnique which is used primarily for rail type systems. With thepreload technique, a guide wire is positioned within an inner lumen ofan OTW device such as a dilatation catheter or stent delivery catheterwith the distal tip of the guide wire just proximal to the distal tip ofthe catheter and then both are advanced through the guiding catheter tothe distal end thereof. The guide wire is first advanced out of thedistal end of the guiding catheter into the patient's coronaryvasculature until the distal end of the guide wire crosses the arteriallocation where the interventional procedure is to be performed, e.g. alesion to be dilated or a dilated region where a stent is to bedeployed.

The catheter, which is slidably mounted onto the guide wire, is advancedout of the guiding catheter into the patient's coronary anatomy over thepreviously introduced guide wire until the operative portion of theintravascular device, e.g. the balloon of a dilatation or a stentdelivery catheter, is positioned across the arterial location. Once thecatheter is in position with the operative means located within thedesired arterial location, the interventional procedure is performed.The catheter can then be removed from the patient over the guide wire.Usually, the guide wire is left in place for a period of time after theprocedure is completed to ensure re-access to the arterial location ifit is necessary. For example, in the event of arterial blockage due todissected lining collapse, a rapid exchange type perfusion ballooncatheter such as described and claimed in U.S. Pat. No. 5,516,336(McInnes et al.), can be advanced over the in-place guide wire so thatthe balloon can be inflated to open up the arterial passageway and allowblood to perfuse through the distal section of the catheter to a distallocation until the dissection is reattached to the arterial wall bynatural healing.

With the bare wire technique, the guide wire is first advanced by itselfthrough the guiding catheter until the distal tip of the guide wireextends beyond the arterial location where the procedure is to beperformed. Then a rail type catheter, such as described in U.S. PatentNo. 5,061,273 (Yock) and the previously discussed McInnes et al. whichare incorporated herein by reference, is mounted onto the proximalportion of the guide wire that extends out of the proximal end of theguiding catheter outside of the patient. The catheter is advanced overthe guide wire, while the position of the guide wire is fixed, until theoperative means on the rail type catheter is disposed within thearterial location where the procedure is to be performed. After theprocedure the intravascular device may be withdrawn from the patientover the guide wire or the guide wire advanced further within thecoronary anatomy for an additional procedure.

Conventional guide wires for angioplasty, stent delivery, atherectomyand other vascular procedures usually comprise an elongated core memberwith one or more tapered sections near the distal end thereof and aflexible body such as a helical coil or a tubular body of polymericmaterial disposed about the distal portion of the core member. Ashapeable member, which may be the distal extremity of the core memberor a separate shaping ribbon secured to the distal extremity of the coremember, extends through the flexible body and is secured to the distalend of the flexible body by soldering, brazing or welding which forms arounded distal tip. Torquing means are provided on the proximal end ofthe core member to rotate, and thereby steer, the guide wire while it isbeing advanced through a patient's vascular system.

Further details of guide wires, and devices associated therewith forvarious interventional procedures can be found in U.S. Pat. No.4,748,986 (Morrison et al.); U.S. Pat. No. 4,538,622 (Samson et al.):U.S. Pat. No. 5,135,503 (Abrams); U.S. Pat. No. 5,341,818 (Abrams etal.); U.S. Pat. No. 5,345,945 (Hodgson, et al.) and U.S. Pat. No.5,636,641 (Fariabi) which are hereby incorporated herein in theirentirety by reference thereto.

One of the difficulties with conventional coil guide wires is that it isdifficult to transmit torque at the distal end of the guide wire. When aconventional coil has a torque applied, depending upon the direction ofthe torque the coil can either expand or contract, but only a percentageof the torque is transmitted to the end of the coil. In the course ofnavigating the guide wire through the patient's vascular and in someprocedures it is necessary to apply a torque at the proximal end of theguide wire to effect a torque at the distal end. With conventional coilsthis can sometimes be difficult. The present invention seeks to addressthis situation by providing a guide wire with flexibility and stiffnesscharacteristics that are equal or superior to the existing coil guidewires but also transmit torque in a more consistent and reliable manner.

SUMMARY OF THE INVENTION

A guide wire of the present invention has a flexible coil section thatis fashioned from a tube made of helically wound strands of metal suchas stainless steel wire forming a first layer that is soldered to a wirecoil serving as a second layer, where the multi-layer construction ofthe inner and outer layers leaves open a hollow center channel forinsertion of a core member. In one preferred embodiment of the presentinvention, the multi-layer flexible coil section is mechanically grounddown to either a constant or tapered outer diameter by removing selectedmaterial from the flexible coil section for desired stiffness andflexibility. The result is a guide wire that has a variable diameterflexible coil section at the distal section of the guide wire forimproved pushability, torque transmission, and tactile response.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view partially in section of a guide wireembodying features of the invention.

FIG. 2 is a cross-sectional view of the guide wire shown in FIG. 1 takenalong lines 2-2.

FIG. 3 is a cross-sectional view of the guide wire shown in FIG. 1 takenalong lines 3-3.

FIG. 4 is a cross-sectional view of the guide wire shown in FIG. 1 takenalong lines 4-4.

FIG. 5 is a cross-sectional view of the guide wire shown in FIG. 1 takenalong lines 5-5.

FIG. 6 is an elevated perspective view of an embodiment of the guidewire of the present invention having a tapered distal end.

FIG. 7 is a sectional view of another embodiment of the presentinvention.

FIG. 8 is a cross-sectional view of the embodiment of FIG. 7 taken alonglines 8-8.

FIG. 9 is a cross-sectional view of the embodiment of FIG. 7 taken alonglines 9-9.

FIG. 10 is a sectional view of another embodiment of the presentinvention.

FIG. 11 is a cross-sectional view of the embodiment of FIG. 10 takenalong lines 11-11.

FIG. 12 is a sectional view of another embodiment of the presentinvention.

FIG. 13 is a sectional view of yet another embodiment of the presentinvention.

FIG. 14 is a cross-sectional view of the embodiment of FIG. 13 takenalong lines 14-14.

FIG. 15 is a cross-sectional view of the embodiment of FIG. 13 takenalong lines 15-15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A guide wire typically includes a flexible wire positioned in an organ,vessel, or duct of a patient for the purpose of directing passage of alarger device threaded over or along the length of the guide wire to adesired location in the vasculature of the patient. A wide variety ofguide wires have been developed for various applications includingmedical applications, such as, but not limited to, coronary angioplasty.Also, endovascular interventions are rapidly advancing as a viablealternative for invasive vascular surgery. During these interventions, aguide wire is generally inserted into a region of a patient, such as thegroin region, and the guide wire is then advanced to a desired location,typically under fluoroscopic guidance. Accurate positioning of the guidewire with respect to the vasculature is a prerequisite for a successfulprocedure. Furthermore, during neuro-interventions, positioning theguide wire accurately is difficult due to the complexity of thevasculature and narrowness of the blood vessels, thereby resulting in anincrease of intervention time and exposure to radiation.

The present invention is directed to an elongated intracorporeal devicesuch as a guide wire constructed of a hollow helical strand about a corecoil. Hollow helical strand wires are available, for example, by FortWayne Metals (http://www.medicalmetals.com) of Fort Wayne, Ind. Theouter layer of the hollow helical strand comprises multiple strands ofmetal wire such as stainless steel, Nitinol, or the like which issoldered to an inner core wire coil. The construction provides bettertorque transmission while maintaining or improving tactile feedback andmaintains a constant diameter under the influence of applied torque.

FIG. 1 is a side elevational view partially in section of one embodimentof the present invention guide wire 10. The guide wire 10 includes anelongated core having a proximal core section 12 and a distal coresection 14. In this embodiment, the entire wire core is made from asingle material such as stainless steel. In various alternativeembodiments (not shown), the proximal core section can be made from ahigh strength steel while the distal core section 14 is made from asuperelastic alloy such as nickel-titanium (e.g., Nitinol) or the like.The two core sections 12,14 can be joined by a weld or adhesive, and/orby an interconnecting hypotube made from various materials.

Returning to FIG. 1, the guide wire 10 includes optional taperedsections 16, 18. Specifically, the present invention contemplates one ormore tapered profiles at varying degrees of taper, although straight,curved, and/or stepped profiles are also contemplated. The guide wire 10further includes a coating 20 disposed on and adhering to the wire core22. The surface coating 20 or the surface of the wire core 22, or both,include color coding as discussed below.

The surface coating 20 may only partially cover the guide wire core 22or may envelope the entire core altogether. The surface coating may be alow friction material such as polytetrafluoroethylene (“PTFE”) that aidsin positioning the guide wire 10. The coating may include positionalmarkers at the distal or proximal end to aid the practitioner inlocating the end portion(s) of the guide wire 10. Toward the distal end24 of the guide wire 10 is typically a flexible member 26. Preferablythe flexible member 26 is one or more helical coils 25,27 welded,bonded, soldered, or otherwise attached to the distal core section 14.In a preferred embodiment, the flexible member is made of a radiopaquematerial such as platinum to help provide accurate positioning of theguide wire. In the embodiment shown, the flexible member 26 is attachedat its proximal end by a weld or solder mass 28 and at its distal end bya solder ball 30 or similar rounded tip. Furthermore, the guide wire 10features a flattened distal tip 32 that extends into the solder ball 30.FIGS. 2, 3, and 4 are cross-sectional views of the guide wire 10 takenalong lines 2-2, 3-3, and 4-4 of FIG. 1, respectively.

The combination of coils 25 and 27, wound in opposite directions,provide the guide wire with a tip section that is both flexible andpossesses enhanced torque capabilities. The distal tip will not easilycoil (or uncoil) when a torque is applied at the proximal end due to thedual nature of the helical coils 25, 27. The present invention has beenfound to enjoy good torque transmission while maintaining good tactilefeedback for guide wires of similar diameters. This is because torqueapplied in the direction of one of the helical coils will be resisted bythe second helical coil, maintaining more of the original torque. Byadvantageously shaving or tapering the diameter of the guide wire's coreor the outer helical coil in the distal direction, the stiffnessproperties can be modified to the needs of the application.

FIG. 6 illustrates the flexible member 26 with first and second helicalcoils 25, 27 without the core section, where the outer helical coil 27has been tapered by shaving the surface beginning at a location 31. Itis to be understood that the tapering of the flexible member can occurat any suitable location to modify the stiffness of the guide wire andthat the depicted taper is merely exemplary.

A second embodiment of the present invention is shown in a sectionalview in FIG. 7. In this embodiment, a distal core section 40 narrows toa first tapered section 42, which supports a constant diameter internalmember 44. Wrapped around the internal member 44 is a first helical coil46 wound in a first direction, and a second helical coil 48 wrappedaround the first helical coil but in the opposite direction. The outerhelical coil 48 is tapered in the distal direction so as to effect areduced stiffness in this direction. A polymer coating 50 surrounds thehelical coils. FIGS. 8 and 9 illustrate cross-sectional views of theguide wire along lines 8-8 and 9-9.

FIG. 10 illustrates another embodiment of the present invention, whichis similar to the embodiment of FIG. 7 but includes a helical coil tip52 about the distal end of the internal core member 44. FIG. 11 shows across-sectional view where coil 46 is wrapped around core 44, and coil48 is wrapped around coil 46, and a gap 54 exists between the polymercoating and the outer helical coil due to the tapering of the outerhelical coil 48. FIG. 12 is yet another embodiment of the presentinvention and comprises the embodiment of FIG. 10 without the plasticcoating.

FIG. 13 is yet another embodiment of the present invention, where theguide wire has a double helical coil positioned at the distal tip of thecore 44. The core 44 has a first tapered section 42 and a second taperedsection 56, which narrows to a constant diameter end section 58. Theconstant diameter end section 58 has a first inner helical coil 46wrapped around it, and a second outer helical coil 48 is wrapped aroundthe first inner helical coil 46. The second outer helical coil 48 istapered in a distal direction to modify the stiffness in that direction,and the helical coils can also include a polymer coating such as thatshown in FIG. 7. FIGS. 14 and 15 illustrate cross sectional views, wherea gap 60 is present in FIG. 15 due to the narrowing of the end section58 from the tapered section 56.

It is to be understood that the foregoing description is intended to beillustrative of embodiments of the present invention but is not intendedto be limiting in any manner. One of ordinary skill in the art willreadily appreciate modifications and alterations to the above describedexamples, and the intention includes all such modifications andalterations. Accordingly, the scope of the invention is properlyinterpreted to be encompassed by the words of the appended claims, usingthe words' ordinary meaning, without limiting the definition of thosewords to the examples provided herein.

1-13. (canceled)
 14. A guide wire for use in a medical procedure,comprising: an elongate flexible member having a distal end and aproximal end, the flexible member comprising a first wire wound into aninner hollow helical coil in a first direction and a second wire woundinto an outer helical coil in a second direction about the inner helicalcoil; and the outer helical coil having a tapered portion.
 15. The guidewire of claim 14, wherein the outer helical coil is shaved to form thetapered portion.
 16. The guide wire of claim 15, wherein the taperedportion extends from the proximal end toward the distal end so that thedistal end is more flexible than the proximal end.
 17. The guide wire ofclaim 16, wherein the outer helical coil has an outer surface that isshaved to form the tapered portion.